A looming Supreme Court decision that could disqualify Prime Minister Nawaz Sharif over corruption allegations had the country on edge on Wednesday, as a drawn-out investigation related to the “Panama Papers” leaks neared a conclusion.

Disqualifying Sharif would leave his party in power, but it would cause intense turmoil at a time when Pakistan is experiencing modest growth and improved security after years of violence, and the civilian government and powerful military have appeared to come to uneasy terms.

Sharif has denied any wrongdoing, but the Supreme Court agreed to investigate his family’s offshore wealth late last year after opposition leader Imran Khan threatened street protests.

The SC could take a range of steps. It could clear the prime minister, or order a further judicial commission of inquiry or even declare him ineligible to hold office, as it did in 2012 with then-Prime Minister Yusuf Raza Gilani over a contempt of court case.

Naeem ul Haque, a spokesman for Khan’s Pakistan Tehreek-e-Insaf (PTI) said he expected a verdict against Sharif, but he made clear the opposition would not launch a new street movement if they were disappointed.

In 2014, Khan led a months-long protest that paralysed the government quarter in the capital, Islamabad, after rejecting Sharif’s decisive election win a year earlier.

The case stems from documents leaked from the Panama-based Mossack Fonseca law firm appeared to show that Sharif’s daughter and two sons owned offshore holding companies registered in the British Virgin Islands and used them to buy properties in London.

Sharif told Parliament last year that his family wealth was acquired legally in the decades before he entered politics and that no money was siphoned off-shore. — Reuters

History’s biggest data leak

The Panama Papers are an unprecedented leak of 11.5m files from the database of the world’s fourth biggest offshore law firm, Mossack Fonseca. The records were obtained from an anonymous source by the German newspaper Süddeutsche Zeitung, which shared them with the International Consortium of Investigative Journalists (ICIJ). The ICIJ then shared them with a large network of international partners, including the Guardian and the BBC.

What do they reveal?

The documents show the myriad ways in which the rich can exploit secretive offshore tax regimes. Twelve national leaders are among 143 politicians, their families and close associates from around the world known to have been using offshore tax havens.

A $2bn trail leads all the way to Vladimir Putin. Among national leaders with offshore wealth are Nawaz Sharif, Pakistan’s PM; Ayad Allawi, ex-interim prime minister and former vice-president of Iraq; Petro Poroshenko, president of Ukraine; Alaa Mubarak, son of Egypt’s former president; and the prime minister of Iceland, Sigmundur Davíð Gunnlaugsson.

What is Mossack Fonseca?

It is a Panama-based law firm whose services include incorporating companies in offshore jurisdictions such as the British Virgin Islands. It administers offshore firms for a yearly fee. Other services include wealth management.

Where is it based?

The firm is Panamanian but runs a worldwide operation. Its website boasts of a global network with 600 people working in 42 countries. It has franchises around the world, where separately owned affiliates sign up new customers and have exclusive rights to use its brand. Mossack Fonseca operates in tax havens including Switzerland, Cyprus and the British Virgin Islands, and in the British crown dependencies Guernsey, Jersey and the Isle of Man.